Research on Performance Evaluation of Different Dosages of Hot Recycled Asphalt Mixtures Based on High Temperature Shear Resistance

Recycled asphalt pavement (RAP) is incorporated into AC-25C asphalt mixture at varying percentages—25%, 40%, and 60%—to assess the high-temperature performance through rutting and uniaxial penetration tests. The research reveals that as the RAP content increases, there is a significant improvement in the high-temperature performance of the asphalt mixture. Notably, at a 40% RAP content, the dynamic stability and penetration strength exhibit the most substantial enhancement. However, at a 60% RAP content, the high-temperature performance of the recycled mixture is markedly lower than at 40%, and the dynamic stability fails to meet the relevant requirements specified in JTG F40–2004. Furthermore, the study observes a notable increase in cohesion (C) as the hot recycled asphalt mixture's RAP content rises, leading to an extended stress retention stage compared to the conventional uniaxial penetration test process. Additionally, the stress retention stage becomes longer with the increasing RAP content.